Assembly of a composite structure may involve locating a charge of composite material on a layup mandrel and subsequently compacting the charge of composite material on the layup mandrel to form an intermediate structure that includes a compacted charge of composite material and the layup mandrel. The compacting may decrease a thickness of the charge of the composite material, remove void space from within the charge of composite material, increase adhesion among a plurality of layers, or plies, that may be present within the charge of composite material, increase adhesion between the charge of composite material and the layup mandrel, increase adhesion between the charge of composite material and materials that already may be present on the layup mandrel, and/or otherwise prepare the intermediate structure for further processing.
Historically, the compacting has been accomplished by a “bagging” process, wherein the charge of composite material and a portion of the layup mandrel are covered with a thin, flexible, polymeric sheet. The polymeric sheet is then taped to the layup mandrel to isolate (or at least substantially isolate) an enclosed volume from fluid communication with the ambient environment. Subsequently, a vacuum is applied to the enclosed volume to decrease a pressure therein, and atmospheric pressure acts upon the charge of composite material, thereby compacting the charge of composite material.
While the above-described procedure may be effective at compacting the charge of composite material, it is a time-consuming, labor-intensive, and material-intensive process that requires custom-fitting the polymeric sheet and manually taping the polymeric sheet to the layup mandrel. In addition, compaction of the charge of composite material onto a surface of the layup mandrel (such as an interior surface thereof) may require oversized polymer sheets that may extend to, past, and/or around a perimeter, or outer perimeter, of the layup mandrel and/or may require correspondingly long lengths of tape so as to prevent contamination of existing materials that may be present on the surface of the layup mandrel. Thus, there exists a need for improved systems and methods for compacting charges of composite material.